This helps people looking at samples on how to use Dawn from getting
confused when implementation-based swapchains break (because they were
just made to be good enough N years ago).
Fixed: dawn:1361
Change-Id: Ia989fca4d0455fb8e0ff754056a3d60eb2958b04
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86531
Reviewed-by: Loko Kung <lokokung@google.com>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>